This invention relates in general to the field of telecommunications and more particularly to a high density unit shelf network interface card and method of operation.
The demand for high capacity and reliable telecommunications networks continues to grow as network and service providers upgrade their networks to provide more and increasingly advanced telecommunications services. In particular, the demand for high capacity and reliable digital cross-connect systems continues to grow. A digital cross-connect system is a specialized type of high-speed digital data and voice channel switch that is partitioned using specific instructions or commands that are separate from the normal signaling network and independent of any information that may flow through the cross-connect system. Reliability and availability are of paramount importance in these systems.
Unfortunately, digital cross-connect systems are often inflexible and have a limited line capacity that is difficult to increase or expand. This presents problems as a telecommunications network expands and the line capacity of the existing digital cross-connect system is met or exceeded. Generally, a telecommunications network designer or planner has no choice but to either replace the existing digital cross-connect system with an entirely new system, having a greater capacity, or to buy an additional digital cross-connect system to work in tandem with the existing digital cross-connect system. Both of these options are expensive, time consuming to install and administer, and often cause an interruption in service. Furthermore, there are often physical space limitations that prevent the location of additional telecommunications hardware such as a digital cross-connect system. As a result, the incremental cost to upgrade a telecommunications system far exceeds any immediate or near-term incremental revenues that will be realized to offset the upgrade cost.
Inflexible digital cross-connect systems present problems when maintenance is needed on the network interface card of a particular circuit or connection. The maintenance of the network interface card often makes the particular circuit or connection unavailable which reduces the overall availability of the circuit or connection.
From the foregoing it may be appreciated that a need has arisen for a high density unit shelf network interface card and method of operation that significantly increases the capacity of an existing digital cross-connect system without having to install an entirely new cross-connect system while improving overall system reliability and availability. In this manner, as the demand for high capacity and reliable telecommunications systems grows, existing digital cross-connect systems may easily and conveniently grow accordingly. Incremental upgrade costs can be minimized and will more closely track incremental increases in revenue as new services and users are added to the telecommunications network. In accordance with the present invention, there is provided a network interface card for a high density unit shelf that substantially eliminate and reduce the disadvantages and problems associated with expanding the capacity of a digital cross-connect system.
According to an aspect of the present invention, a network interface card is provided for use with a digital cross-connect system that includes an inbound processing circuit operable to process an inbound telecommunications signal having a first format into an inbound telecommunications signal having a second format. Also included is an outbound processing circuit operable to process an outbound telecommunications signal having the second format into an outbound telecommunications signal having the first format.
The present invention provides a multitude of technical advantages. One technical advantage of the present invention includes the capability to easily and inexpensively upgrade the capacity of an existing digital switch, such as a digital cross-connect system, while increasing overall system reliability and availability. The reliability and availability are increased by providing physically redundant paths for inbound telecommunications signals and outbound telecommunications signals while providing a path for information to be exchanged between the two network interface ports of each network interface port pair. Another technical advantage of the present invention includes the flexibility to configure the high density unit shelf in such a manner as to minimize incremental costs as the capacity of the associated digital cross-connect system expands. Yet another technical advantage includes the capability to interface network signals provided at a variety of different signal formats and rates to the digital cross-connect system using the high density unit shelf of the present invention. Still yet another technical advantage of the present invention includes the capability to operate in either a redundant mode or a non-redundant mode. Yet another technical advantage includes the capability to upgrade the capacity of a digital switch, such as a digital cross-connect system, with a high density unit shelf that consumes minimal floor space. Another technical advantage of the present invention includes the capability to keep a circuit or connection in service while performing maintenance on the network interface card of the circuit or connection while still maintaining the circuit or connection in service, thus significantly increasing overall availability and reliability. Other technical advantages may be readily apparent to one skilled in the art from the following figures, description, and claims.